Thermostat.



A. DOB LE. THERMOSTAT.

APPLICATION FILED JUNE 13,1912.

1,099,029, Patented June 2, 1914.

invention consists of the apparatus illus- ABNEQE DOBLE, OF WALTHAM, MASSACHUSETTS.

rnnarrosrar.

Specification of Letters Patent.

Application filed June 13, 1912. Serial No. 708,488.

Patented June 2, 1914.

To all whom c't'may concern Be it known that I, ABNER DOBLE, a citizen of the United States, residing at Wal tham, in'the county'of Middlesex, State of Massachusetts, have invented certain new and useful Improvements in Thermostats,

' of which the following is a specification.

This invention relates to thermostats and more particularly to thermostats used inconnection with steam motor vehicles for regulating the supply of water or fuel to the steam generator.

The invention is especially adapted for use in connection with the regulating system shown in my prior application No. 643,420 filed August 10, 1911, although as will be readily understood the invention is adapted for use in connection with other systems.

I Thermostats have been usually constructed heretofore with a copper thermostatic element. Under the action of the highly superheated steam; which is used on motor vehicles the copper on the thermostatic element rapidly deteriorates and therefore renders the thermostat unreliable.

It is therefore one of the objects of this invention to provide an improved thermostat in which the thermostatic element is made from seamless steel tubing. 1 Another object of the invention is to provide means for automatically compensating for the expansion and, contraction of the parts of the thermostat due to changes in the atmospheric temperature.

With these and otherolojects in view the trated in. the accompanying drawing which 1 is an elevation with certain parts shown in through this tube.

fixed in a suitable bracket 12 secured to the section.

In the drawing 10 indicates a portion of the vehicle frame which is preferably made of steel. A seamless steel tube 11 is connected with the steam generator of the vehicle in such manner that the steam in passing from the generator to the engine flows One end of the tube is therein a valve 19 having a stem 20 which is connected to or formed integral with the rod 16, the latter passing through a suitable stuiiing box 21 at the end of the casing 17 The invention is illustrated as controlling the water supply to the generator, the water being admitted to the casing 17 by means of .a suitable pipe 22 and being conducted from the casing to the generator, not shown, by

means of a pipe 23. y

The rods 16 and 20 are preferably made of copper or composition metal which has a relatively high co-efiicient of expansion. On the rod l6 is anadjustable nut 24: which forms an abutment for the eye 15. At the end of the rod 16 is an abutment 25 between which and the eye is arranged a spring 26. The co-eiiicient of expansion of the rods 16 and is approximately twice that of the steel frame 10, and therefore inorder to compensate for variations in the length of the frame 10 due to changes in atmospheric temperature the distance between the abutment 2?: and the valve 19 is made substantially one-half of the, distance between the brackets 12 and '18. Since the spring 26 tends to move the rod 16 so as to close the valve 19 it will be seen that the valve 19 will be closed at all times except when the tube 11 expands until the'eye 15 engages the abutment and forces the valve oh its seat, thus admitting an additional supply of Water to the generator. "This takes place when the temperature of the superheated steam exceeds a predetermined degree' When the temperature of the steam is belowtemperature of the tube 11 does not change with changes in the atmospheric temperature, but the frame 10 and the rods 16 and 20' will ordinarily be at the same temper ature as the atmosphere. At zero-degrees centigrade temperature the distance between the brackets 12 and 18 on the frame 10 will be-a definite amount and at degrees centi grade the distance between these brackets will be somewhat greater. The distance between the abutment 2i andthe valve 19 will be a definite amount at zero degrees can tigrade, and since this distance is approximately one-half of the distance between the brackets 12 and 18 and the co-eficient of expansion of tlie rods 16 and 20 is approximately twice that of the frame 10', it will be seen that the distance between the abfitment 24 and the valve 19 will always correspond with the distance between the brackets 12 and 18 so that the operation of the thermostat is not affected by changes in atmospheric temperature.

While I prefer to make the frame 10 and the tube 11 of steel it will be understood that the invention is not limited to the use of this metal as I may use any otherv metal and arrange the various parts in such a manner as to produce the same eitect as is produced by the arrangement above described.

Having thus described the invention what.

is claimed as new is:

1. In a thermostat, the combination of a support, a thermostatic tube having one end secured to the support and having at its other end an arm provided with 'an eye, a valve body secured to said support, a valve in said body adapted to control the flow of a fluid, a rod connected with said valve for actuating the same and extending through said eye, an abutment on said rod adapted to be engaged by said arm to open said valve by the expansion of said tube, and a spring abutting said arm and said rod adapted to efiiect the closing of said valve and to yield after the valve is closed, as said tube contracts.

2. In a thermostat, the combination of a metallic support, a steel thermostatic tube having one end secured to said support, an arm secured to the other end of said tube and having an opening therein, a valve body secured to said support, a valve in said body adapted to control the flow of fluid therethrough, a rod connected to said valve and passing through said eye, and an adjustable abutment on said rod adapted to be engaged by said arm to move the valve in one direction, a second abutment on said'rod on the opposite side of said arm from the first abutment, and a spring bearing against said second abutment and said arm and tending to move said second abutment away from said arm.

3. In a thermostat, the combination of a metallic support, a steel thermostatic tube having one end secured to said support, a

valve body secured to said support, a valve I in said body adapted to control the flow of fluid therethrough, a rod connected to said valve, said rod having a higher co-eificient of expansion than said support, means connecting said rod with said thermostatic tube whereby the valve is actuated by said tube, said parts being so constructed and arranged that the expansion of said support due to changes in the atmospheric temperature are compensated for by the corresponding changes in the length of said rod.

a. In a thermostat, the combination with a steel support, a thermostatic tube having one end thereof secured to said support, means for guiding the other end of said tube, a valve body secured to said support, a Valve in said body adapted to control the flow of fluid therethrough, a rod connected to said valve, said rod having a co-eiiicient of expansion approximately double that of the steel support, an abutment on said rod, an

arm secured to said tube and adapted to engage said abutment to move said valve in one direction, the distance between said abutment and said valve being substantially one half of the distance between the points at which said tube and said valve body are connected to said support.

5. In a thermostat, the combination of a metallic support, a thermostatic tube having one end thereof secured to said support, an arm secured to the other end of said tube, a valve body secured to said support, a valve in said body adapted to control the flow of fluid therethrough, a rod connected to sald valve for actuating the same, an abutment on 

